1. Technical Field
The present invention relates to a light emitting device, a super-luminescent diode, and a projector.
2. Related Art
A super-luminescent diode (hereinafter also referred to as an “SLD”) is a semiconductor light emitting device capable of providing an output up to several hundreds of mW with a single device similarly to a semiconductor laser, while showing a broadband spectrum and thus being incoherent shape similarly to an ordinary light emitting diode.
The SLD can be used as, for example, alight source of a projector, and for realizing a small-sized and high-brightness projector, it is required to use a light source with high light output and low etendue. In order to achieve this, it is preferable that the lights emitted from a plurality of gain regions travel in the same direction. In JP-A-2010-3833 (Document 1), by combining the gain region having a linear shape and the gain region having a winded shape at a reflection surface, the lights respectively emitted from the light emitting sections of the two gain regions are made to proceed in the same direction.
To reduce loss of the optical system and number of optical components, there has been proposed a type of a projector that can perform light collection (including light collimation or reduction in diffusion angle of light) and uniform illumination at the same time by providing the SLD immediately below the light valve and using a lens array. In the projector of that type described above, it is required to provide the light emitting sections in accordance with the intervals of the lens array. In the technology described in Document 1, it is difficult to arrange the plurality of light emitting sections with intervals corresponding to a variety of lens arrays with different pitches, and therefore, it is not achievable to apply the technology to the projector of the type described above.